```xml Vector Tile Cartography Notes
Vector Tile Cartography Notes

1. Layer Data Content

2. Layer Properties and Styles

3. Thematic Maps

4. Text Style

5. Point Symbols

6. Line Symbols

7. Fill Symbols

8. Map Properties Settings

9. Vector Tile Generation Configuration

10. Vector Tile Update

This document summarizes the SuperMap map styles and settings that are supported or not supported by SuperMap vector tiles. It defines clear capability boundaries to help users create vector maps suitable for vector tile production.

SuperMap supports generating vector tiles (.mvt) that follow the MapBox MVT specification from vector maps. The tile data contains the geometry and attributes of features, while the feature styles are described by the MapBox standard style file (style.json) and follow the MapBox GL version 8 style specification. For more information about MapBox styles, see: https://www.mapbox.com/mapbox-gl-style-spec.

Vector tiles generated by SuperMap will be displayed on the SuperMap iClient client based on the MapBox style file. The client uses MapBox GL or OpenLayers to render and display vector tiles. OpenLayers supports rendering vector tiles with multiple projections, while MapBox GL only supports rendering vector tiles with the EPSG:3857 projection.

When generating vector tiles, the program needs to translate the SuperMap map style into the MapBox style description. However, some SuperMap map styles and settings are not supported by MapBox and cannot be translated into the MapBox style description. Therefore, the display effects of the generated vector tiles may not be consistent with the original map, or some styles and map settings may be lost.

Map Content, Rendering Styles, and Related Settings Supported by Vector Tiles Remarks
1. Layer Data Content
Vector Dataset 2D Point, Line, Region, Text Dataset Supported Raster data layers are not supported. If the map contains unsupported dataset layers, those layers will be ignored when generating vector tiles.
If the geometry contains too many sub-objects, it will affect the tile generation speed. It is recommended to split sub-objects to improve efficiency.
The style of EPS data layers in the map cannot be converted to the vector tile style description, meaning the style cannot be output.
3D Point, Line, Region, Text Dataset Supported
EPS (Tsinghua Shanwei) Point, Line, Region, Text Dataset Partially Supported
Other Datasets Not Supported
Geometry Complexity     For massive polygon data, to improve the efficiency of vector tile generation and display, it is necessary to simplify the data. Whether to apply simplification depends on the actual data situation.
  • For data sources other than PostGIS, simplification during vector tile generation is specified by the "Rarefy Display" parameter. Checking this option means simplification is applied; otherwise, not.
  • For PostGIS data sources, modify the SuperMap.xml file (located in the SuperMap iDesktopX installation directory/BIn/) to add the "<MVTSimplifyPGIS>TRUE</MVTSimplifyPGIS>" tag. The default value is TRUE (simplification); set to FALSE to disable simplification.
For polygon objects with dense nodes and complex shapes, after simplification at small scales, the resulting vector tiles may have deformed polygon objects. For example:
  • For area rivers at small scales, after simplification, the objects may be significantly deformed. It is recommended that users ensure the map has reasonable complexity at different display scales. Here, it is suggested to use line objects to represent rivers at small scales.
  • For tens of millions of earth polygon data, after simplification at small scales, polygon deformation may cause hollow areas in the map. It is recommended to first create a vector pyramid for massive earth polygon data before generating vector tiles.
Vector Data Coordinate System     If the data's coordinate system differs from the map's display coordinate system, the system will perform coordinate system transformation on the data during vector tile generation, converting it to the map's display coordinate system. If the map data is large, this operation will consume significant disk space and tile generation time. It is recommended to first transform the data's coordinate system to the map's display coordinate system before generating vector tiles.
2. Layer Properties and Styles
Layer Visible Scale Range Minimum and Maximum Visible Scale Supported Vector tiles use global scales. The visible scale range of layers in the vector map should be adjusted according to the global scale; otherwise, the visibility of map features in the vector tiles may be inconsistent with the original map.
The layer visible scale values and their numerical precision must exactly match the global scale.
Layer Display Filter Filter Expression Partially Supported When "Separate Data from Style" is checked during vector tile generation:
Only simple logical relationships and comparison operations are supported.
  • Comparison operators supported: =, <, >, !=. The values used in expressions can only be numeric. Text or characters are not supported, i.e., expressions like "NAME = 'Sichuan Province'" are not supported.
  • Logical relationship: And, Or, Not are supported.
Fields in filter expressions must not include the table name, i.e., expressions like "China_Province.pop_2014 > 3833" are not supported.
When the filter expression used by a point label differs from that of its corresponding layer (thematic map or normal layer), the resulting vector tile will use the label's filter expression.
When "Separate Data from Style" is not checked during vector tile generation:
Layer display filters are unrestricted. Only data meeting the filter conditions will be output to the tile data, effectively reducing tile size.
Layer Join Attribute Table Setting   Not Supported  
Aggregation of Normal Layers and Thematic Layers    
  • In the same map, for the same point/line/region dataset, at most one thematic map and one label thematic map based on that dataset can coexist; otherwise, the effect may not meet expectations. However, this restriction does not apply when the display filters of multiple label thematic maps have no intersecting search results.
  • In the same map, for the same point dataset, at most one unique value thematic map and one single-value label thematic map based on that dataset can coexist, and both must use the same field for the single value.
Alternative: If multiple thematic maps are needed for a point/line/region dataset, layer groups can be used to separate them. That is, create multiple layer groups, ensuring that each layer group contains at most one thematic map and one label thematic map based on that dataset. In the same layer group, for the same point dataset, at most one unique value thematic map and one single-value label thematic map can coexist, and both must use the same field for the single value.
Labels and their corresponding vector layers must be in the same layer group, and the label layer must be positioned above the corresponding vector layer.
Minimum Object Size   Supported  
Layer Blend Mode   Not Supported  
Scale with Map   Not Supported  
Weight   Not Supported  
Simplification Display Settings   Not Supported  
Filter Small Overlapping Objects Setting   Not Supported  
Object Display Order   Not Supported  
Symbol Layer Drawing   Not Supported  
3. Thematic Maps
Unique Value Thematic Map Single Value Expression Partially Supported Only a single field is supported. Field expressions and SQL function results are not supported, e.g., name || ‘_’ || type is not supported.
Note: Vector tiles do not display objects where the field value is NULL.
Property Field Defining Marker Style Partially Supported Version 12.0.0 and above, only point unique value thematic maps support controlling symbol rotation angle through field styles. Otherwise, setting symbols, colors, sizes, and rotation angles through attribute fields is not supported.
Offset Setting for Thematic Layers Not Supported  
Marker Style Partially Supported See the sections "Point Symbols," "Line Symbols," and "Fill Symbols" for details.
Traffic Situation Configuration Not Supported  
Graduated Color Thematic Map Segmentation Expression Supported Only a single field is supported. Field expressions and SQL function results are not supported.
Segmentation Method Supported  
Segmentation Precision Supported  
Marker Style Partially Supported See the sections "Point Symbols," "Line Symbols," and "Fill Symbols" for details.
Uniform Label Thematic Map Label Expression Partially Supported For the labeling field used by the label thematic map, only a single field is supported. Field expressions and SQL function results are not supported, e.g., name || ‘_’ || type is not supported.
Label Background Partially Supported
  • Background shape: Supports rectangle, rounded rectangle, and point symbols; does not support diamond, ellipse, or triangle.
  • Background style: Only solid fill is supported; rounded rectangle backgrounds support setting fill borders, rectangles do not.
  • Background margin: Supported.
  • Background shadow effect: Not supported.
For the same point dataset, when both a point normal layer and a label thematic map based on that layer exist, MapBox does not support setting both a point symbol and a label background; otherwise, the point symbol will be lost. Although the label is retained, the label background will deviate from the label text.
When the label background uses a point symbol, the point symbol will not automatically adjust size with the label length.
Label Offset Supported Note: The independent offset configuration for multiple label thematic maps along the vertical direction of the same line object, added in version 12.1.0 to achieve non-overlapping layered display effects for multiple labels, is not supported for output to vector tiles.
Leader Line Not Supported  
Label and Point Alignment Partially Supported Left baseline, right baseline, and center baseline alignment are not supported.
Repeat Dimension Removal Settings Not Supported
Overlap and Avoidance Settings (Flow, No Overlap) Not Supported The avoidance handling of features in MapBox differs from SuperMap, causing discrepancies in the number of displayed labels and label-to-point alignment between the two.
Text Layout (Long Text Handling, Line Breaks, Multi-line Text Alignment, Landscape Display Tags) Not Supported MapBox's handling of long label line breaks differs from SuperMap. When the label thematic map applies label line break settings and multi-line text layout settings, the display effects in generated vector tiles may differ significantly from the original map.
Text Avoidance Tile Range Not Supported
(Supported in 12.0.1 and above)		  
Label Height Range Not Supported  
Superscript/Subscript Not Supported Does not support superscript/subscript display effects created with label expressions.
Text Style Settings Partially Supported See the "Text Style" section for details.
Label Along Line Direction Partially Supported MapBox style only supports two directions for labels along a line (normal direction and top-to-bottom, left-to-right). If the map uses other directions, the vector tile will place labels in the "top-to-bottom, left-to-right" direction.
Show Slivers Not Supported  
Spacing for Labels Along Line Supported
(Supported in 12.0.0 and above)
 MapBox's handling of labels along lines differs from SuperMap, so the display effects of labels along lines in vector tiles may differ from the original map. For example, the effect of periodic spacing along the line may differ.
When a fixed text angle is set for labels along lines, the "Label Drawing Type" must be set to "Entire Draw," otherwise, the fixed text angle will be invalid in vector tiles.
Relative Angle of Characters Along Line Not Supported
Label Along Line Mode Not Supported
Fixed Text Angle Supported
Remove Duplicate Labels Not Supported
Periodic Spacing Along Line Supported
Label Drawing Type Along Line (Split Draw, Entire Draw, Compatible Draw, etc.) Not Supported
Single-Value Label Thematic Map Single Value Field Partially Supported Only a single field is supported. Field expressions and SQL function results are not supported, e.g., name || ‘_’ || type is not supported.
For the same point dataset, if both a unique value thematic map and a single-value label thematic map based on that dataset exist, both must use the same field for the single value.
Other Settings Consistent with Uniform Label Thematic Map  
Custom Thematic Map   Not Supported If the map contains unsupported thematic maps, those thematic layers will be ignored when generating vector tiles.
Matrix Label Thematic Map   Not Supported
Graduated Symbol Thematic Map   Not Supported
Statistical Thematic Map   Not Supported
Dot Density Thematic Map   Not Supported
Aggregation Maps (Heat Map, Grid Map, etc.)   Not Supported
4. Text Style
Font   Supported Ensure the corresponding font files exist on the computer.
Text Color   Supported  
Font Size   Supported  
Font Effects Bold Supported When bold and italic effects are used, ensure that the corresponding bold and italic font library files exist on the computer; otherwise, the effects may not be applied in generated vector tiles.
Italic Supported
Outline Supported  
Shadow Not Supported  
Underline Not Supported  
Strikethrough Not Supported  
Rotation Angle Supported  
Slant (Left Slant, Right Slant, Slant Angle) Not Supported  
Fixed Size Supported When generating vector tiles, text in the map needs to have a fixed size; otherwise, the displayed text effect in tiles may differ from the original map.
Text Background Not Supported Text background in vector tiles will be displayed as text outline.
Superscript/Subscript Not Supported  
Text Layout Multi-line Text Alignment, etc. Not Supported  
5. Point Symbols
System Point Symbols System0 Not Supported The System0 square point symbol will be displayed as a circular point symbol in vector tiles.
Workaround: Create a new point symbol with a square geometry.
System1 Supported  
Vector Point Symbols   Supported  
Raster Point Symbols   Supported  
Color   Supported  
Symbol Rotation Angle   Supported  
Symbol Transparency   Not Supported  
Scale with Map   Not Supported  
6. Line Symbols
System Line Types System0, System1 Supported  
System2, System3, System4 Not Supported System2, System3, and System4 line types will be displayed as solid lines in vector tiles.
Alternative: Create a new line type, add a dash (system line type) sub-line, and adjust the virtual-real mode of the sub-line to create the desired dashed line type.
Custom Line Types   Supported Custom line types support line symbols containing multiple sub-lines, but each sub-line type must be "default".
Sub-line Type Dash (System Line Type) Supported Supports virtual-real mode.
Other Sub-line Types Not Supported Unsupported sub-lines will be displayed as solid lines in vector tiles.
Sub-line Settings End Symbol Not Supported  
Sub-line Offset Not Supported  
Scale with Map   Not Supported  
7. Fill Symbols
System Fill Symbols System0, System1, System2, System3, System4, System5, System6, System7 Supported  
Fill Symbol Border   Consistent with Line Symbols MapBox's support for area symbol outlines is the same as for line type symbols.
Custom Fill Symbols   Supported Custom fill symbols only support symbols containing one fill sub-layer, which can be image filling or symbol fill.
Fill Symbol Sub-layers Symbol Filling Supported For versions below 12.0.0, symbols with only one sub-layer are supported, with fill methods including point symbol filling, image fill, solid fill, and linear filling.
For versions 12.0.0 and above, symbols with multiple sub-layers are supported, with fill methods including point symbol filling, image fill, solid fill, and linear filling.
Image Filling Supported
Scale with Map   Not Supported  
8. Map Properties Settings
Map Fixed Scale   Supported Vector tiles use global scales. The fixed scale of the vector map should be adjusted according to the global scale; otherwise, the visibility of map features in the vector tiles may be inconsistent with the original map.
The layer visible scale values and their numerical precision must exactly match the global scale.
Map Overlap Settings   Not Supported Version 12.0.0 and above only support disabling map overlap settings for "Show/Hide Points with Text".
Map Rotation Angle   Not Supported  
Fixed Symbol Angle   Not Supported  
Fixed Text Angle   Not Supported  
Fixed Text Direction   Not Supported  
Line Antialiasing   Not Supported  
Text Antialiasing   Not Supported  
Label Weight Setting   Not Supported  
9. Vector Tile Generation Configuration
Tile Scale Global Scale Supported  
Custom Scale Not Supported  
Tile Level Range Continuous Scale Levels Supported  
Discontinuous Scale Levels Supported If the scale levels are discontinuous, display effects at missing levels may be abnormal when viewing vector tiles.
Storage Format Compact Supported  
Original Supported  
MongoDB Supported  
Storage Path Local Directory Supported  
Shared Directory Not Supported  
FTP Directory Not Supported  
Object Storage Path Partially Supported Only vector tiles in the original storage format can be stored in object storage.
Tile Bounds Whole Map Supported Default tile extent.
Current Window (Desktop) Supported Not supported by GPA tools.
Custom Range - Rectangle Range Supported GPA tools specify using "left, top, right, bottom" coordinates.
Custom Range - Specify the Object (Desktop) Supported Not supported by GPA tools.
Custom Range - Custom Expression (Desktop) Not Supported  
Origin of Tile Modify Origin of Tile Not Supported  
Vector Tile Parameters Generate Font Cache File Supported Enable "Generate Font Cache File"; otherwise, text content in result vector tiles may be abnormal.
Generate Vector Tiles Supported Generate vector tiles.
In vector tile update scenarios:
When separating data from style, if the vector map data has not changed but the map style has changed, and the style does not use new field content, when updating vector tiles, it is not necessary to regenerate vector tiles; only regenerate the tile style. In this case, this option can be disabled.
Generate Tile Style Supported Generate vector tile style.
In vector tile update scenarios:
When separating data from style, if only the vector map data has been updated but the map style has